The present invention is related to a HVAC system for use in a vehicle. In particular, the system uses a compressor control system that enhances the overall performance of the HVAC system.
Passenger comfort and fuel efficiency have set forth increasing demands on automotive heating, ventilating and air-conditioning (HVAC) systems. It is a primary goal of most HVAC systems to provide a more efficient means for providing climate control to an automobile.
In particular, the air conditioning (AC) system of an automobile utilizes a compressor that is either mechanically or electrically driven to circulate an automotive refrigerant to cool the interior passenger compartment of an automobile. Typically, the compressor is activated in response to a user demand such as a cooling request which will activate the compressor. Generally, there is no separate control of the compressor""s operation other than switching it on and off.
A scroll compressor has superior noise characteristics to a piston-cylinder compressor. However, a scroll compressor""s ability to control capacity is not as good. Accordingly, there is a trade-off in capacity control and noise between these two compressors.
The capacity of a scroll compressor with a control valve cannot be limited to a low enough point where evaporator core freeze can be avoided. Therefore, the compressor must be shut on and off to control capacity and evaporator core freeze.
Therefore, there is a need for a control system wherein the operation of the compressor is optimized in order to increase the overall performance of the compressor and the vehicle.
It is therefore an object of the invention to provide an improvement in the performance of a HVAC system of an automotive vehicle.
Another object is to provide a method and apparatus for supplementing and/or improving the HVAC system of an automotive vehicle.
Another object of the present invention is to link the compressor control to the temperature of the evaporator fins.
Another object of the present invention is to utilize a control algorithm resident upon a microprocessor within the HVAC control head. The control algorithm will cycle the compressor in response to the evaporator fin temperature.